Morphological Differences Research Articles

Two new nocturnal species of South Asian Cnemaspis Strauch, 1887 (Squamata: Gekkonidae) of the wynadensis clade from the southern Western Ghats, India

We describe two new medium-bodied, nocturnal species of South Asian Cnemaspis from the southern Western Ghats, Tamil Nadu, India in an integrative taxonomic framework. The two new species are phylogenetically and morphologically allied to the wynadensis clade and can be distinguished from other species of the wynadensis clade and each other by a combination of nonoverlapping morphological characters including body size, homogeneous dorsal pholidosis, the number of femoral pores and poreless scales separating these series, the number of ventral scales across the midbody and longitudinal scales from mental to cloaca, the number of dorsal granules around the body; and an uncorrected pairwise ND2 sequence divergence of 8.2–22.9 % (16S 4.2–12.2 %) from all other members in the clade. These are the first members of the wynadensis clade known from south of the Palghat Gap apart from C. bireticulata, a putative junior synonym of C. sisparensis that is likely to be distinct owing to morphological differences and geographic distance. Cnemaspis sanctus sp. nov. is from low coastal hills in Kanyakumari District at the southern tip of the Western Ghats and Cnemaspis persephone sp. nov. is from the Anaimalais, Anaimalai Tiger Reserve. Many more undescribed species of the wynadensis clade and South Asian Cnemaspis are likely to be found across the southern Western Ghats.

Oral mucosa - an examination map for confocal laser endomicroscopy within the oral cavity: an experimental clinical study

ObjectivesConfocal laser endomicroscopy (CLE) is an optical method that enables microscopic visualization of oral mucosa. Previous studies have shown that it is possible to differentiate between physiological and malignant oral mucosa. However, differences in mucosal architecture were not taken into account. The objective was to map the different oral mucosal morphologies and to establish a “CLE map” of physiological mucosa as baseline for further application of this powerful technology.Materials and methodsThe CLE database consisted of 27 patients. The following spots were examined: (1) upper lip (intraoral) (2) alveolar ridge (3) lateral tongue (4) floor of the mouth (5) hard palate (6) intercalary line. All sequences were examined by two CLE experts for morphological differences and video quality.ResultsAnalysis revealed clear differences in image quality and possibility of depicting tissue morphologies between the various localizations of oral mucosa: imaging of the alveolar ridge and hard palate showed visually most discriminative tissue morphology. Labial mucosa was also visualized well using CLE. Here, typical morphological features such as uniform cells with regular intercellular gaps and vessels could be clearly depicted. Image generation and evaluation was particularly difficult in the area of the buccal mucosa, the lateral tongue and the floor of the mouth.ConclusionA physiological “CLE map” for the entire oral cavity could be created for the first time.Clinical relevanceThis will make it possible to take into account the existing physiological morphological features when differentiating between normal mucosa and oral squamous cell carcinoma in future work.

Optimization of the ETL titanium dioxide layer for inorganic perovskite solar cells

Titanium dioxide layers are the most popular electron transport layer (ETL) in perovskite solar cells. However most studies focuses on mesoporous structure and application with organic–inorganic hybrid perovskite. In this study, the topic of ETL in planar structure of inorganic CsPbBr3 perovskite solar cells was tackled, the presented approach will reduce production costs and improve cell stability, which is the greatest drawback of perovskite cells especially organic–inorganic perovskite. The potential application of these technology are greenhouses and building integrated PV sector. Here, the two TiO2 precursors titanium(IV) ethoxide in ethanol and titanium(IV) bis(acetylacetonate) diisopropoxide (Tiacac) were investigated, optimized and compared. TiO2 layers were deposited on high roughness FTO, without the use of a mesoporous layer, by spin coating method. The correlation between stock solution concentration and thickness of manufactured layers was tracked for both precursors as well as their difference in morphology of the final films and other properties. In particular, conformality and optical properties are better for Tiacac. Slightly lower refractive index of Tiacac-based titania reduced the reflective losses from 7.3 to 6.9% effectively. The obtained layers were used for inorganic solar cells of CsPbBr3 perovskite to finally settle the issue of optimal thickness and precursor. It is interesting that despite the supremacy in investigated properties of commonly used of the precursor Tiacac, the results of the cells pointed to the Tieth. The efficiency of the champion cell is 6.08% for Tieth, while 5.62% is noted for Tiacac. Trying to figure out this riddle, we shed a new light on the phenomena going on the ETL/inorganic perovskite interface investigating nanoroughness.

Co-sensitization of Copper Indium Gallium Disulfide and Indium Sulfide on Zinc Oxide Nanostructures: Effect of Morphology in Electrochemical Carbon Dioxide Reduction.

Recent advances in nanoparticle materials can facilitate the electro-reduction of carbon dioxide (CO2) to form valuable products with high selectivity. Copper (Cu)-based electrodes are promising candidates to drive efficient and selective CO2 reduction. However, the application of Cu-based chalcopyrite semiconductors in the electrocatalytic reduction of CO2 is still limited. This study demonstrated that novel zinc oxide (ZnO)/copper indium gallium sulfide (CIGS)/indium sulfide (InS) heterojunction electrodes could be used in effective CO2 reduction for formic acid production. It has been determined that Faradaic efficiencies for formic acid production using ZnO nanowire (NW) and nanoflower (NF) structures vary due to structural and morphological differences. A ZnO NW/CIGS/InS heterojunction electrode resulted in the highest efficiency of 77.2% and 0.35 mA cm-2 of current density at a -0.24 V (vs. reversible hydrogen electrode) bias potential. Adding a ZTO intermediate layer by the spray pyrolysis method decreased the yield of formic acid and increased the yield of H2. Our work offers a new heterojunction electrode for efficient formic acid production via cost-effective and scalable CO2 reduction.

A new subgenus of hard ticks, Filippoviella n. subgen. (Acari: Ixodidae) comprising Ixodes trianguliceps Birula, 1895 and I. ghilarovi Filippova & Panova, 1988, parasites of small mammals in Europe and Asia

We establish a new subgenus, Filippoviella n. subgen. (Acari: Ixodidae) based on two species formerly assigned to the subgenus Exopalpiger Schulze, 1935 in the genus Ixodes Latreille, 1795. Ixodes (Filippoviella) trianguliceps Birula, 1895 is a tick species broadly distributed throughout Europe and western Siberia, the females, nymphs and larvae of which mostly feed on small mammals such as shrews and rodents. Ixodes (Filippoviella) ghilarovi Filippova & Panova, 1988 is found in the Caucasus region on rodents and shrews. The type species of this new subgenus is Ixodes trianguliceps. The major morphological differences allowing discrimination of the two species of Filippoviella n. subgen from members of the subgenus Exopalpiger are the shape of the idiosoma, shape of the basis capituli, development of palpal segment I, the suture between palpal segments II and III, development of syncoxae and chaetotaxy. We sequenced the entire mitochondrial genome of I. trianguliceps; according to our phylogeny from 10 protein-coding mitochondrial genes of 17 of the 23 Ixodes subgenera (34 spp.), I. (Filippoviella) trianguliceps is basal to the “other Ixodes” and polyphyletic with I. (Exopalpiger) fecialis Warburton & Nuttall, 1909.

A mutation associated with resistance to synthetic pyrethroids is widespread in US populations of the tropical lineage of Rhipicephalus sanguineus s.l

The brown dog tick, Rhipicephalus sanguineus sensu lato (s.l.), is an important vector for Rickettsia rickettsii, causative agent of Rocky Mountain spotted fever. Current public health prevention and control efforts to protect people involve preventing tick infestations on domestic animals and in and around houses. Primary prevention tools rely on acaricides, often synthetic pyrethroids (SPs); resistance to this chemical class is widespread in ticks and other arthropods. Rhipicephalus sanguineus s.l. is a complex that likely contains multiple unique species and although the distribution of this complex is global, there are differences in morphology, ecology, and perhaps vector competence among these major lineages. Two major lineages within Rh. sanguineus s.l., commonly referred to as temperate and tropical, have been documented from multiple locations in North America, but are thought to occupy different ecological niches. To evaluate potential acaricide resistance and better define the distributions of the tropical and temperate lineages throughout the US and in northern Mexico, we employed a highly multiplexed amplicon sequencing approach to characterize sequence diversity at: 1) three loci within the voltage-gated sodium channel (VGSC) gene, which contains numerous genetic mutations associated with resistance to SPs; 2) a region of the gamma-aminobutyric acid-gated chloride channel gene (GABA-Cl) containing several mutations associated with dieldrin/fipronil resistance in other species; and 3) three mitochondrial genes (COI, 12S, and 16S). We utilized a geographically diverse set of Rh sanguineus s.l. collected from domestic pets in the US in 2013 and a smaller set of ticks collected from canines in Baja California, Mexico in 2021. We determined that a single nucleotide polymorphism (T2134C) in domain III segment 6 of the VGSC, which has previously been associated with SP resistance in Rh. sanguineus s.l., was widespread and abundant in tropical lineage ticks (>50 %) but absent from the temperate lineage, suggesting that resistance to SPs may be common in the tropical lineage. We found evidence of multiple copies of GABA-Cl in ticks from both lineages, with some copies containing mutations associated with fipronil resistance in other species, but the effects of these patterns on fipronil resistance in Rh. sanguineus s.l. are currently unknown. The tropical lineage was abundant and geographically widespread, accounting for 79 % of analyzed ticks and present at 13/14 collection sites. The temperate and tropical lineages co-occurred in four US states, and as far north as New York. None of the ticks we examined were positive for Rickettsia rickettsii or Rickettsia massiliae.

Architecture engineering enables high-stability 2D/multi-2D heterostructured MXene/TiO2 for boosting solar-driven CO2 reduction

Photocatalytic CO2 reduction to produce value-added products is considered a promising solution to solve the global energy crisis and the greenhouse effect. In this study, 2D/multi-2D heterostructures were successfully synthesized through electrostatic self-assembly between Ti3C2 and TiO2 nanosheets. The optimal sample (15TC/TiO2) shows yields of 209.98 and 28.09 μmol·g−1·h−1 for CO and CH4, respectively. According to the characterization and simulation study, the enhanced performance is mostly attributable to the 2D/multi-2D heterostructures, which are formed from two phases with huge differences in morphology and size, enabling the development of multiple tiny contact surfaces to increase the effective contact area. In addition, the TiO2 nanosheets utilized in the construction have up to 80 % exposure to the (001) facets, which offer catalytically active sites. This work provides a feasible method for constructing 2D/multi-2D heterostructure catalyst materials.

Characterization of Interfacial Corrosion Behavior of Hybrid Laminate EN AW-6082 ∪ CFRP.

The corrosion behavior of a hybrid laminate consisting of laser-structured aluminum EN AW-6082 ∪ carbon fiber-reinforced polymer was investigated. Specimens were corroded in aqueous NaCl electrolyte (0.1 mol/L) over a period of up to 31 days and characterized continuously by means of scanning electron and light microscopy, supplemented by energy dispersive X-ray spectroscopy. Comparative linear sweep voltammetry was employed on the first and seventh day of the corrosion experiment. The influence of different laser morphologies and production process parameters on corrosion behavior was compared. The corrosion reaction mainly arises from the aluminum component and shows distinct differences in long-term corrosion morphology between pure EN AW-6082 and the hybrid laminate. Compared to short-term investigations, a strong influence of galvanic corrosion on the interface is assumed. No distinct influences of different laser structuring and process parameters on the corrosion behavior were detected. Weight measurements suggest a continuous loss of mass attributed to the detachment of corrosion products.

Species -shared and -unique gyral peaks on human and macaque brains

Cortical folding is an important feature of primate brains that plays a crucial role in various cognitive and behavioral processes. Extensive research has revealed both similarities and differences in folding morphology and brain function among primates including macaque and human. The folding morphology is the basis of brain function, making cross-species studies on folding morphology important for understanding brain function and species evolution. However, prior studies on cross-species folding morphology mainly focused on partial regions of the cortex instead of the entire brain. Previously, our research defined a whole-brain landmark based on folding morphology: the gyral peak. It was found to exist stably across individuals and ages in both human and macaque brains. Shared and unique gyral peaks in human and macaque are identified in this study, and their similarities and differences in spatial distribution, anatomical morphology, and functional connectivity were also dicussed.

Species -shared and -unique gyral peaks on human and macaque brains.

Cortical folding is an important feature of primate brains that plays a crucial role in various cognitive and behavioral processes. Extensive research has revealed both similarities and differences in folding morphology and brain function among primates including macaque and human. The folding morphology is the basis of brain function, making cross-species studies on folding morphology important for understanding brain function and species evolution. However, prior studies on cross-species folding morphology mainly focused on partial regions of the cortex instead of the entire brain. Previously, our research defined a whole-brain landmark based on folding morphology: the gyral peak. It was found to exist stably across individuals and ages in both human and macaque brains. Shared and unique gyral peaks in human and macaque are identified in this study, and their similarities and differences in spatial distribution, anatomical morphology, and functional connectivity were also dicussed.

<i>Amaranthus emarginatus</i> s.lat. (Amaranthaceae) in Italy

Amaranthus emarginatus belongs to the Amaranthus blitum complex, a critical taxonomic group. Within the variability of A. emarginatus, two taxa are often accepted, ‘emarginatus’ and ‘pseudogracilis’, which differ by habitus, synflorescence structure, and leaf size. However, their taxonomic value is debated, and A. emarginatus itself is sometimes included in A. blitum as subspecies. In this paper, molecular, morphological, phytogeographical, and ecological data are discussed to assess the most correct rank of these taxa. We conclude that A. emarginatus deserves specific distinctness from A. blitum, and A. pseudogracilis can be regarded as a subspecies of the former. This choice reflects both the molecular data and geographical distributions of A. blitum and A. emarginatus, i.e., Mediterranean area, Europe, and North Africa for the former vs. neotropics for the latter). Within A. emarginatus, in addition, to the different morphology, A. emarginatus var. pseudogracilis differs also on account of its ecological preferences, because it occurs in warm and humid areas, whereas A. emarginatus var. emarginatus is better adapted to cold and dry habitats. However, since molecular analyses cannot clearly separate the two taxa, we consider the subspecific rank as the most appropriate. We also found a further morphological difference in seed coat ornamentation, hitherto not pointed out: the shape of the peripheral cells is tetragonal in A. emarginatus subsp. pseudogracilis, but polygonal (cells with ≥ 5 sides) in subsp. emarginatus. Distributional maps and status assessment at regional level for the two taxa are provided. According to this revision, A. emarginatus subsp. emarginatus is to be regared as naturalized in central and southern Italy (Latium and Campania, respectively).

Hybrid Fabrication of Cold Metal Transfer Additive Manufacturing and Laser Metal Deposition for Ti6Al4V: The Microstructure and Dynamic/Static Mechanical Properties.

The titanium alloy components utilized in the aviation field are typically large in size and possess complex structures. By utilizing multiple additive manufacturing processes, the precision and efficiency requirements of production can be met. We investigated the hybrid additive manufacturing of Ti-6Al-4V using a combination of cold metal transfer additive manufacturing (CMTAM) and laser metal deposition (LMD), as well as the feasibility of using the CMT-LMD hybrid additive manufacturing process for fabricating Ti-6Al-4V components. Microstructural examinations, tensile testing coupled with digital image correlation and dynamic compressive experiments (by the split Hopkinson pressure bar (SHPB) system) were employed to assess the parts. The results indicate that the interface of the LMD and CMTAM zone formed a compact metallurgical bonding. In the CMTAM and LMD zone, the prior-β grains exhibit epitaxial growth, forming columnar prior-β grains. Due to laser remelting, the CMT-LMD hybrid additive zone experiences grain refinement, resulting in equiaxed prior-β grains at the interface with an average grain size smaller than that of the CMTAM and LMD regions. The microstructures reveal significant differences in grain orientation and morphology among the zones, with distinct textures forming in each zone. In the CMT-LMD hybrid zone, due to interfacial strengthening, strain concentration occurs in the arc additive zone during tensile testing, leading to fracture on the CMTAM zone. Under high-strain-rate dynamic impact conditions, the LMD region exhibits ductile fracture, while the CMTAM zone demonstrates brittle fracture. The hybrid zone combines ductile and brittle fracture modes, and the CMT-LMD hybrid material exhibits superior dynamic impact performance compared to the single deposition zone.

An integrative taxonomic study on needlefishes (Belonidae) unveils two new species within the genus Ablennes from the Indian Ocean

The needlefish genus Ablennes remains monotypic, characterized by the globally distributed flat needlefish known as Ablennes hians. Their taxonomy has been mired with ambiguities due to the greater-than-average morphological variations observed in samples from different regions. Utilizing integrated taxonomic methods relying on mitochondrial molecular markers, it was revealed that the species initially perceived as a single entity is, in fact, a complex comprising at least three different species. In this context, we introduce two new species: Ablennes joseberchmansis sp. nov. and Ablennes gracalii sp. nov., They are morphologically distinct: in view of the morphometry and meristic characteristics. A. joseberchmansis sp. nov. and A. gracalii sp. nov. display distinct differentiation characteristics from A. hians in terms of dorsal fin, nostril position, dorsal fin origin, vertebrae count, scale counts, head length, eye diameter, interorbital width, maxilla length, dorsal ray height, depth at pelvic origin, lower lobe of the caudal fin, and caudal peduncle depthcaudal peduncle depth. These variations highlight their unique morphological traits and aid in their differentiation within the genus Ablennes. We assessed genetic relationships using a Maximum likelihood (ML) phylogenetic tree, revealing three distinct clades of morphological differences in Ablennes specimens from different morphological groups. The genetic variation, as represented by Kimura 2 parameter (K2P) distances, within the three Ablennes species spans from 6.5% to 9.4%. More specifically, we observed a 7.5% genetic difference between A. hians and A. joseberchmansis sp. nov., and a 6.5% distinction between A. hians and A. gracalii sp. nov. The interspecies divergence between the two newly identified species measured at 9.4%. These findings, which showcase the genetic distinctions among the three morphologically distinct Ablennes specimens, provide strong confirmation for the existence of three separate species within the Ablennes genus of needlefish in the Indian Ocean.

Single‐Molecule Characterization and Super‐Resolution Imaging of Alzheimer's Disease‐Relevant Tau Aggregates in Human Samples

AbstractHyperphosphorylation and aggregation of the protein tau play key roles in the development of Alzheimer's disease (AD). While the molecular structure of the filamentous tau aggregates has been determined to atomic resolution, there is far less information available about the smaller, soluble aggregates, which are believed to be more toxic. Traditional techniques are limited to bulk measures and struggle to identify individual aggregates in complex biological samples. To address this, we developed a novel single‐molecule pull‐down‐based assay (MAPTau) to detect and characterize individual tau aggregates in AD and control post‐mortem brain and biofluids. Using MAPTau, we report the quantity, as well as the size and circularity of tau aggregates measured using super‐resolution microscopy, revealing AD‐specific differences in tau aggregate morphology. By adapting MAPTau to detect multiple phosphorylation markers in individual aggregates using two‐color coincidence detection, we derived compositional profiles of the individual aggregates. We find an AD‐specific phosphorylation profile of tau aggregates with more than 80 % containing multiple phosphorylations, compared to 5 % in age‐matched non‐AD controls. Our results show that MAPTau is able to identify disease‐specific subpopulations of tau aggregates phosphorylated at different sites, that are invisible to other methods and enable the study of disease mechanisms and diagnosis.

Single-Molecule Characterization and Super-Resolution Imaging of Alzheimer's Disease-Relevant Tau Aggregates in Human Samples.

Hyperphosphorylation and aggregation of the protein tau play key roles in the development of Alzheimer's disease (AD). While the molecular structure of the filamentous tau aggregates has been determined to atomic resolution, there is far less information available about the smaller, soluble aggregates, which are believed to be more toxic. Traditional techniques are limited to bulk measures and struggle to identify individual aggregates in complex biological samples. To address this, we developed a novel single-molecule pull-down-based assay (MAPTau) to detect and characterize individual tau aggregates in AD and control post-mortem brain and biofluids. Using MAPTau, we report the quantity, as well as the size and circularity of tau aggregates measured using super-resolution microscopy, revealing AD-specific differences in tau aggregate morphology. By adapting MAPTau to detect multiple phosphorylation markers in individual aggregates using two-color coincidence detection, we derived compositional profiles of the individual aggregates. We find an AD-specific phosphorylation profile of tau aggregates with more than 80 % containing multiple phosphorylations, compared to 5 % in age-matched non-AD controls. Our results show that MAPTau is able to identify disease-specific subpopulations of tau aggregates phosphorylated at different sites, that are invisible to other methods and enable the study of disease mechanisms and diagnosis.

Plant invasion alters movement behaviour in endangered butterflies but not their morphology or genetic variability

AbstractInvasions of alien plants often result in biodiversity loss and may impact the biology of native species. However, the effects of biological invasions on the behavioural responses of native species have rarely been investigated. We studied how the alteration of habitat due to the invasion of alien goldenrod (Solidago spp) affects a native butterfly, the scarce large blue Phengaris teleius, which is a flagship species for grassland biodiversity conservation. To better understand immediate responses in flight behaviour (daily movements, resting, and dispersal) to a new habitat, we performed observations of experimentally translocated butterflies of two origins (invaded vs. non-invaded habitats) to four different environments: invaded habitat, non-invaded habitat, invaded matrix, non-invaded matrix. Moreover, we tested whether the level of invasion may be related to the variation in morphological traits associated with flight (wing size, body mass) and genetic variability. Flight behaviour was affected by the high goldenrod cover and the sex of the butterflies, regardless of the butterflies’ origin. In the habitat and matrix invaded by goldenrod, the butterflies tended to display dispersal behaviour more often compared to the non-invaded ones. Flight distances were longest in the matrix with goldenrod and resting time was longest in habitats invaded by goldenrod. Analysis of morphological traits as well as eight microsatellite loci did not reveal significant differences in morphology or genetic variation among the populations studied.

Museum genomics approach to study the taxonomy and evolution of Woolly-necked storks using historic specimens.

The accessibility of genomic tools in evolutionary biology has allowed for a thorough exploration of various evolutionary processes associated with adaptation and speciation. However, genomic studies in natural systems present numerous challenges, reflecting the inherent complexities of studying organisms in their native habitats. The utilization of museum specimens for genomics research has received increased attention in recent times, facilitated by advancements in ancient DNA techniques. In this study, we have utilized a museum genomics approach to analyze historic specimens of Woolly-necked storks (Ciconia spp.) and examine their genetic composition and taxonomic status and explore the evolutionary and adaptive trajectories of populations over the years. The Woolly-necked storks are distributed in Asia and Africa with a taxonomic classification that has been a matter of ambiguity. Asian and African Woollynecks were recently recognized as different species based on their morphological differences; however, their genomic validation was lacking. In this study, we have used ∼70-year-old museum samples for whole-genome population-scale sequencing. Our study has revealed that Asian and African Woollynecks are genetically distinct, consistent with the current taxonomic classification based on morphological features. However, we also found a high genetic divergence between the Asian subspecies Ciconia episcopus neglecta and Ciconia episcopus episcopus, suggesting this classification requires a detailed examination to explore processes of ongoing speciation. Because taxonomic classification directly impacts conservation efforts, and there is evidence of declining populations of Asian Woollynecks in Southeast Asia, our results highlight that population-scale studies are urgent to determine the genetic, ecological, and phylogenetic diversity of these birds.

Diel and Vertical Niche Differentiation of Frugivore Communities Feeding on Ficus nota (Blanco) Merr.

Ficus species are keystone species in tropical ecosystems for frugivores. Nonetheless, ecological aspects of fig frugivory such as niche differentiation are understudied, leading to huge gaps in the knowledge of fig-frugivore interactions. We used camera traps to monitor the vertical and diel activity of frugivores feeding on a Ficus nota tree in Cavite, the Philippines for 70 d to determine vertebrate species feeding on Ficus nota and their niche differentiation mechanisms. We observed several mammalian taxa (pteropodid fruit bats, Rattus sp. and Paradoxurus philippinensis) and several avian taxa (Hypsipetes philippinus, Pycnonotus goiavier, Lanius cristatus, and Centropus viridis). All of the detected species were observed to be perching on, inspecting, or eating fruits. However, based on existing literature, two of the four bird species detected (L. cristatus and C. viridis) are known to be carnivorous. Diel niche differentiation was evident from the diurnal and nocturnal activity patterns of birds and mammals, respectively. We also detected temporal activity differences between pteropodids and P. philippinensis, hence suggesting temporal niche differentiation. Pteropodids were also more active in the terrestrial stratum, whereas non-pteropodids were more active in the arboreal stratum, hence suggesting vertical niche differentiation. Diel niche differentiation may be attributed to differences in food acquisition adaptations, whereas vertical niche differentiation may be attributed to differences in tree morphology between strata and in frugivore adaptations for mobility. These results show that Ficus nota acts as a food source and habitat for frugivores and non-frugivores and that interspecific interactions are mediated by niche differentiation. Our findings underscore the potential of Ficus nota as a species in restoration efforts to support seed-dispersing frugivores and other wildlife species, as well as the utility of camera trapping to survey frugivores in understudied habitats.

Identity, Pathogenicity, and Genetic Diversity of Lasiodiplodia Species Associated with Stem-End Rot of Avocado in China.

Stem-end rot (SER) causes brown necrotic lesions in the pulp near the base of the fruit pedicel and is one of the most devastating postharvest diseases of avocados in all avocado-growing regions of the world. China's avocado industry is growing very rapidly, and the planting area is expanding, but little is known about the pathogens and genetic diversity of avocado SER. To determine the causal agents of SER, avocado fruits were sampled from the main avocado-producing areas in China during 2020 and 2021. Fungal isolates were obtained from SER symptomatic avocado fruits and identified by morphology combined with phylogenetic analysis of internal transcribed spacer (ITS), translation elongation factor 1-α (EF1-α), and β-tubulin (TUB2) gene sequences. All 101 isolates belonged to Lasiodiplodia spp.; four Lasiodiplodia species were identified, namely, L. pseudotheobromae (59.41%), L. theobromae (24.75%), L. mahajangana (7.92%), and L. euphorbiaceicola (1.98%); and six others are classified as Lasiodiplodia sp. (5.94%). There were only slight morphological differences in colonies and conidia of these four species of Lasiodiplodia. The pathogenicity tests showed symptoms of SER, and 92.08% of the isolates exhibited a high level of virulence on avocado (disease index >70), related to the disease severity on avocado fruits. All tested isolates grew well under the temperature ranging from 23 to 33°C. There was a significant difference in mycelial growth between the four species of Lasiodiplodia after treatment with high or low temperatures. The growth of L. pseudotheobromae was the fastest at 13 to 18°C but was the lowest at 38°C (P < 0.05). The red pigment could be produced by all tested isolates after culturing for 7 days at 38°C. The mycelial growth rate was the fastest on PDA medium, and the slowest on the OMA medium but promoted spore formation (P < 0.05). In addition, the genetic diversity of pathogenic Lasiodiplodia species associated with SER collected from avocado, mango, guava, and soursop fruits was determined. A total of 74 isolates were clustered into four main ISSR groups by the unweighted pair-group method with arithmetic mean analysis, and the classification of this group was related to the host. Extensive diversity was detected in the Lasiodiplodia populations. The diverse geographical origins and host species significantly influenced the population differentiation, and most of the genetic variation occurred within populations (P < 0.001). This is the first study to identify the major pathogens of avocado SER in China, survey their occurrence and pathogenicity, and include a comparative analysis of genetic diversity with Lasiodiplodia spp. causing SER on other fruit hosts. Collectively, the Lasiodiplodia species complex affecting avocado showed high pathogenicity and diversity, while L. pseudotheobromae was the most frequently isolated species in China. The results of this study provide insights into the aspects of the epidemic of SER disease caused by Lasiodiplodia species, which will help in developing strategies for the management and control of SER in avocado.

A description of Aliichlorella ignota gen. et sp. nov. and a comparison of the efficiency of species delimitation methods in the Chlorella‐clade (Trebouxiophyceae, Chlorophyta)

AbstractThe present study reports a new representative of Chlorella‐clade that was newly isolated from the Lake Vos'merka (Samara region, Russian Federation). 18S–ITS1–5.8S–ITS2 sequence analyses indicated that the studied strain ACSSI 368 and related Chlorella chlorelloides, Chlorella pulchelloides, formed an separate cluster in the Chlorella‐clade, unrelated to the holotype of the genus Chlorella – Chlorella vulgaris. The independent place of the genus was also confirmed by genetic distances. The individual species status of the studied strain ACSSI 368, compared with the sister C. chlorelloides, was confirmed by morphological differences (cell number per colony, type of chloroplast, number of autospores), genetic distances of the interspecific level by 18S–ITS1–5.8S–ITS2 fragment, alone by internal transcribed spacer 1 (ITS1) and internal transcribed spacer 2 (ITS2) sequences, one complementary base change in ITS1, and the results of species delimitation using five methods. A description of studied strain ACSSI 368 was provided as an authentic strain of the type species Aliichlorella ignota. Currently, the new genus Aliichlorella also includes Aliichlorella chlorelloides comb. nov. and Aliichlorella pulchelloides comb. nov. In general, six different delimitation algorithms were used in the present study. The ASAP (i.e. assemble species by automatic partitioning) and LocMin (i.e. ‘local minimum’ function) algorithms showed synchronous results, but their accuracy with respect to closely related species was somewhat lower. The mlPTP algorithm simultaneously aimed to combine closely related species in one and at the same time divide slightly distinguishing strains within a species into several molecular operational taxonomic units. The bPTP algorithm separated excessively Chlorella‐clade representatives into individual species. The generalized mixed Yule coalescent (GMYC) algorithm results were consistent the most with the modern understanding of the Chlorella‐clade taxonomy. However, the same method is one of the most time‐consuming because, for its implementation, it is necessary to carry out long preparatory work. The KoT results were less accurate than the GMYC results, although this is less time‐consuming because it does not require the preliminary construction of ultrametric trees.